Chemistry Revision on Structure & Bonding

Bonding
1. Ionic
  1. metals lose electrons and become positive
  2. non-metals gain electrons and become negative
  3. has high melting and boiling points
  4. does not conduct electricity when solid
2. Covalent
  1. non-metals only
  2. electrons are shared
  3. Covalent Compounds
    1. have no free electrons
    2. do not conduct electricity
    3. usually gases or liquids at room temp.
  4. bonds between atoms are strong
  5. intermolecular forces are weak
Alloys
1. mixture of metals
2. different sized atoms
3. layers are distorted
4. difficult for layers to slide over each other
5. harder than the pure metal
Polymers
1. Thermosoftening
  1. intermolecular forces are weak
  2. melt at low temps.
  3. little energy needed to break forces
  4. not suitable for packaging hot food
2. Catalyst
  1. speeds up reaction
  2. does not get used up
Graphite and Diamond
1. Graphite
  1. each carbon atom is covalently bonded to three others
  2. has free electrons
    1. conducts electricity
  3. layers are able to slide over each other
  4. weak intermolecular between layers
2. Diamond
  1. each carbon atom is covalently bonded to four others
  2. has no free electrons
    1. does not conduct electricity
  3. no atoms are able to move/slide
Nanoparticles
1. between 1 and 100 nm in size
2. have large surface areas than normal sized particles

Resumo de Recurso

	Criado por Lorna N quase 9 anos atrás